URL Name-Value Pairs

Developers should be aware of a number of useful name-value pairs that can be added to CiviCRM URLs. The most prominent are that after enabling debugging (Administer > Configure > Global Settings > Debugging), the following are active:

Smarty Debug Window - Loads all variables available to the current page template into a pop-up window. To trigger, add &smartyDebug=1 to any CiviCRM URL query string. Make sure you have pop-up blocking disabled in your browser for the CiviCRM site URL.
Session Reset - Resets all values in your client session. To trigger, add &sessionReset=2
Directory Cleanup -Empties template cache and/or temporary upload file folders.
- To empty template cache (civicrm/templates_c folder), add &directoryCleanup=1
- To remove temporary upload files (civicrm/upload folder), add &directoryCleanup=2
- To cleanup both, add &directoryCleanup=3
Stack Trace - To display a stack trace listing at the top of a page, add &backtrace=1
Rebuild Menus - civicrm/menu/rebuild?reset=1

Others affect output format provided by numerous CiviCRM pages:

&snippet=1 provides HTML snippet of main page content rather than full page (Eg http://forum.civicrm.org/index.php/topic,8787.0.html)

&key=myCiviCRMSiteKey required for REST interface (http://wiki.civicrm.org/confluence/display/CRM/REST+interface)

&name=myUFLoginName required for REST signin (http://wiki.civicrm.org/confluence/display/CRM/REST+interface) where myUFLoginName is my user framework (ie Drupal or Joomla) login name

&password=myUFPassword required for REST signin

&json=1 provides JSON data output from REST interface (otherwise data is returned as XML)

&force=1 causes data queries for the url to be rerun, and is especially useful in search based scenarios when data params have changed